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Effects of slurry acidification on soil N 2 O fluxes and denitrification
Author(s) -
Malique Francois,
Wangari Elizabeth,
AndradeLinares Diana Rocío,
Schloter Michael,
Wolf Benjamin,
Dannenmann Michael,
Schulz Stefanie,
ButterbachBahl Klaus
Publication year - 2021
Publication title -
journal of plant nutrition and soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 1436-8730
DOI - 10.1002/jpln.202100095
Subject(s) - denitrification , nitrous oxide , slurry , soil water , volatilisation , environmental science , chemistry , soil acidification , environmental chemistry , ammonium , fertilizer , ammonia , agronomy , soil ph , ammonia volatilization from urea , nitrogen , zoology , environmental engineering , soil science , biology , organic chemistry
Background Reductions of ammonia volatilization resulting from slurry applications to intensively managed grassland may be achieved via slurry acidification. However, it remains uncertain if this may result in pollution swapping, that is, due to reduced ammonia volatilization and increased soil N availability, emission of nitrous oxide from soils may increase. Aims In this study, we compared control (no fertilizer) and slurry fertilized grassland treatments [not acidified (S) and acidified (AS)] to assess whether slurry acidification results in changes of soil N availability, denitrification potential and activity as well as soil fluxes of nitrous oxide. Methods The study was carried out in a montane grassland system in southern Germany, and parameters were followed over a 43‐days period with continuous measurements of soil GHG fluxes and biweekly measurements of microbial and soil parameters preceding and following two fertilizing events. Results Over the entire observation period cumulative N 2 O emissions were significantly elevated for treatments receiving slurry applications, with differences between acidified and non‐acidified slurry treatments being overall insignificant. Transcripts of the nirK type nitrite reductase showed significantly higher numbers in soils of the AS treatment. While soil potential denitrification rates (PDR) did not differ between treatments, there was a strong tendency of increased PDRs for the AS treatment. Conclusions Against expectation, we did not find that application of AS affects PDR or soil N 2 O emissions significantly, though in tendency higher rates of soil N 2 O emissions as well as higher potential denitrification rates were found in treatments receiving acidified slurry as compared to the slurry only treatment. Our results indicate that longer observation periods and given the significant spatial variability, higher numbers of replicates are needed, to finally assess if slurry application indeed results in increased soil denitrification activity, soil N 2 O production and soil‐atmosphere N 2 O emissions.